How to replace hex characters in SQL-Script?

I've got a table that contains rows having the 'NUL' (x'00') in a varchar string.  It's not just that character by itself, but mixed in with other printable ones and the occasional CR or LF.  I'm looking for a way to replace these with blanks.  I've tried what seems like it should work in SQLscript:

     REPLACE(field, x'00', ' ')

...and this does not generate an error, but it doesn't do the replacement either.  Checking further it seems that a hex or binary constant isn't being interpreted, so it's not just the sometimes-problematic NUL.

Currently at SPS06, going to SPS09; I can look up my HANA Studio version if that matters...

Thanks In Advance,

Donn